Systems requiring the payout of feed line during deployment typically present a potential feed line entanglement problem. An example of one such system is the U.S. Navy's anti-personnel obstacle breaching system (APOBS) disclosed in "Reliable and Effective Line Charge System," U.S. patent application Ser. No. 09/12,932, filed on Jan. 24, 1998. Briefly, the APOBS is a portable explosive line charge system used for mine and obstacle neutralization. The system includes a rocket tethered by a line to a series of charges distributed in a spaced-apart fashion along a detonation cord.
As witnessed during developmental testing, the line experiences standing wave motion as the rocket propels itself down range. The distributed line charge moves through the standing wave similar to the way a wave travels down a rope that has been whipped up and down. However, rather than the wave moving through the distributed line charge, the distributed line charge moves through the wave as it flies down range. This gives the appearance that the wave is stationary above the ground and along the flight path. The standing wave causes the line to whip the distributed line charge and create acceleration loads that act in multiple directions which tend to cause line charge fuze failure, charge rupture and general entanglement of both the line and distributed line charge.